thompson



(No Model.) 7 3 S heets-rSheet'L D. M. THOMPSON.

STEAM GENERATOR. No. 601,486. Patented Mar. 29,1898.

Fig- 1 WITNEEEIE.

INVENTUH.

(No Model.) 3 Sheets-Sheet 2.

D. M. THOMPSON; STEAM GENERATOR.

No. 601,486. Patented Mar. 29; 1898. Fig". 2-

WITNIEEES. INYZNZ'UH:

(No Model.) 3 Shets-Sheet 3.

D. M. THOMPSON.

I STEAM GENERATOR.

No. 601,486 Patented ManZQ, 1898.

UNITED STATES DAVID M. THOMPSON, OF PROVIDENCE, RHODE ISLAND.

STEAM-G EN ERATOR.

SPECIFICATION forming part of Letters Patent N 0. 601,486, dated March29, 1898. Application filed June 2, 1897- Serial No. 639,095. (Nomodel.)

To all whom it may concern:

Be it known that I, DAVID M. THOMPSON, of Providence, in the county ofProvidence and State of Rhode Island, have invented a new and usefulImprovement in Steam-Generators; and I hereby declare that the followingis a full, clear, and exact description of the same, reference being hadto the accompanying drawings, forming part of this specification.

This invention has reference to an improvement in steam-boilers andfurnaces connected therewith. y

In the economic generation of power the steam-generator performs themost important function, because the most perfect steam-engine canutilize only a portion of the heat stored up-in the steam-generator. Tosecure the best and most economic results, the fuel must be burned underthe most favorable conditions possible for the perfect combustion of thecarbon in the fuel and of the volatile gaseous products disengaged bythe heat and the disintegration of the fuel on the grate. Not onlymustthe proper quantity of air be supplied to the fuel and the gases,but the gases must have ample room to expand, time for each atom tocombine with the oxygen of the air, and, above all, the gaseous productsmust be maintained at a high temperature until every atom of carbon isconsumed and converted into heat.

The heat produced by the combustion of fuel may be divided into the heatof the products of combustion, which in passing through the fines ortubes of the steam-generator is absorbed by the water and stored up foruseful work, and radiated heat, which can be refiected and deflected,but always acts locally on the surfaces surrounding the incandescentfuel or flame.

One object of this invention is to construct the furnace of asteam-generator so that the gaseous products of combustion may expandand,while the atomic mixture is facilitated,be maintained at a hightemperature to facilitate the perfect combustion of the same.

Another object of the invention is to so arrange the furnace that theexpanded mixed and highly-heated products of combustion from one gratewill pass over the incandescent fuel of another grate and then enter acombustion-chamber before they enter the tubes of the steam-generator.

Another object of the invention is to utilize the radiated heat of afurnace of the abovementioned construction by conducting the same intothe feed-Water supplied to the generator.

Another object of the invention is to prevent the deposit of soot in thetubes of a steam-generator and the discharge of black smoke; and anotherobject of the invention is to more completely separate the impuritiesheld in suspension in the feed-water before the water enters the mainbody of the steamgenerator.

To these ends the invention consists in the peculiar and novelconstruction of the furnaces and the combination of the parts, as willbe more fully described hereinafter and more particularly pointed out inthe claims.

I have elected to illustrate in the" drawings the furnaces as applied toa vertical tubular boiler, showing the preferred form of construction,but do not wish to confine myself to the use of the furnaces inconnection with this particular form or construction of the boiler.

Figure l is a vertical sectional view showing the furnaces in connectionwith a vertical tubular steam-boiler and auxiliary watertubesteam-generators. Fi g. 2 is a transverse sectional view of thefurnaces, showing the water-jacket inclosing the furnaces and thegenerating-tubes extending through the furnaces. Fig. 3 is a horizontalsection on the line X X of Fig. 1, showing the flame-chamberconnectingthe two furnaces.

Similar letters of reference indicate corresponding parts in all thefigures.

In the drawings, A indicates the furnace to which fuel is being suppliedor has last been supplied, and A the furnace in which the fuel is in theincandescent state after the more volatile carbon has passed off. Thetwo furnaces are separated by the partition-wall A which extends fromthe front to or nearly to the end of the grates A A They are in closedby the side Walls A A and covered by the arches A A preferably offire-brick, restin g on the side Walls and the partition-wall A The twofurnaces A and A are connected at the rear by the large preferablysemicircular flame-chamber A and at the front by the opening A in whichthe swinging gate A is placed. This gate A controls the exit from thefurnaces to the combustion-chamber A, and by swinging the gate from oneside to the other either one of the furnaces may be connected with thecombustion-chamber A Under the grates are the ash-pits A A and on therear ends of the grates are the bridge-walls A A An opening connects therear of the ash-pits with the Vault A in which the car A forms aconvenient receptacle for the removal of the ashes.

The jacket A extends over the side walls of the furnaces around, thewall of the flamechamber, and over the arch of the combustion-chamber.The jacket is made up of sections containing each two or morecompartments A separated by partitions having the openings A to formconnections between all the chambers or cells in each section. Thesections are connected by the pipes A with the water-supply and with thepipes A by which the heated water is delivered directly to the boiler orto a settling-chamber connected with the boiler, as is shown in Fig. 1,or to a pump, by which it is delivered to the boiler.

The furnaces are provided with any suitable fire and ash-pit doors anddevices forcontrolling the draft and air-supply.

I will now describe the operations of the furnaces in their normalcondition when the fires have been burning for a sufficient time to heatthe fire-brick sides and arches and with the gate A in the positionshown in Fig. 2, using bituminous or other coal liable to pro- 1 ducethe objectionable black smoke.

The coal supplied in the usual manner to the fire in the furnace A is,owing to the fire and the great heat of the fire-brick or otherrefractory material of the sides and arch of the furnace, quicklyheated, so as to rapidly disengage the volatile gases rich in carbon.These gases and the air drawn into the furnace expand and pass in nearlystraight currents over the bridge-wall and enter the semicircular archedspace of the flame-chamber, where by the change in the direction of thecurrents, the shape of the arched roof, the increased area of thechamber, and the heat of the walls the gases and air mix and burst intoflame. The complete combustion of all the carbon in the gases and theprevention of smoke is so much a matter of atomic mixture, time, andheat that to secure the desired result I pass the gases from theflame-chamber through the furnace A, over the incandescent fuel on thegrate of this furnace, and through the draft-opening A into the archedcombustion-chamber A, where the now thoroughly mixed and heated gasescan again expand and, under the influence of the heat of this chamber,form a final and complete union of the oxygen of the air with any atomsof carbon still remaining in the products of com bustion.

Two arched openings A A lower than the arch of the combustion-chamber Aconnect the combustion-chamber with the chamber A under the verticaltubular boiler B and permit the heated products of combus tion to passthrough the tubes of the boiler to the chimney. The heated products ofcombustion may be conveyed from the combustion-chamber A to any otherform or construction of boiler.

The combustion of the fuel in this furnace is so complete that, as nocarbon can pass through the boiler, the smoke is of a light color,nearly invisible, because it contains no coloring-matter. No sootcollects in the tubes or on any other part of the'boiler, and fine ashesare collected in the flame-chamber, the combustion-chamber, and thechamber A because by the increased area of these chambers the velocityof the flow of the gases is reduced and ashes or incombustible matter isprecipitated in these chambers.

The boiler B, preferably used in connection with the furnaces, as shownin Fig. 1, is a vertical tubular boiler having the central open space E,surrounded by the tubes B The central space B connects with the centralwater-column B extending from the lower tube-sheet of the boilerdownward to the muddrum B The circulating-tube B preferably providedwith a funnel-shaped upper end, is placed into the water-column B anddivides the same into a central descending and an annular ascendingspace.

The mud-drum 13 connects with the transverse chamber B, provided on thetwo opposite sides with the mud-drums B B The i blow-off pipes B Bconnect with the muddrums B B and the blow-off pipe 13 connects with themud-drum B. These blow-off pipes are provided with proper gate valves,as shown in Fig. 1, and the impurities collected in these mud drums maybe discharged through these blow-pipes from the bottom of the mud-drumsas often as the nature of the water used requires.

The series of water-tubes B are connected with the transverse chamber Babove the two mud-drums B B and extend upward through the flame chamberon an easy curve and extend in an upward-inclined direction through thefurnaces A and A and have their other ends secured in one of thechambers B B located at the front of the boiler, which front is providedwith suitable doors by which access is had to the chambers 13. Anotherseries of water-tubes B extend in an inclined direction from each of thechambers B, through the combustion-chamber A and the chamber A to thefitting 13 which is connected with the steam-generator by the pipe 13. Apipe B extends from each of the fittings B downward and connects thesame with one of the mud-drums B By this construction the two water-tubesections, one from each furnace, are in all respects independent of eachother and free to expand and contract.

with the pipe A The steam generated in each is delivered by the pipe Bto the boiler, and perfect circulation of the water in each section issecured by the pipe B which forms a direct connection between the upperends of the water-tubes of each section with the lower water connectionof the tubes. The rapid circulation of the water in these tubes B and Band their exposure to the direct action of therays of heat from the fireand the flame in the furnaces inclosed by the refractory materialsecures an evaporative efficiency of the highest value.

The feed-water, as has been hereinbefore described, is heated in thecellular jacket A, the several sections of which are connected The pipeB may connect the pipe A with the feed-pipe B", as is shown in Fig. 1;but I prefer to connect the pipe A with a steam or feed pump and connectthe pump with the feed-pipe B", so as to relieve the cellular jacketfrom the pressure of the steam and the static pressure of the water inthe boiler-and subject the jacket only to the pressure incident to theweight of the water in the jacket. The feed pipe terminates, preferably,in a rose B and the feed-water is delivered into the mud-drum Bpreferably at a point below the ash-pit.

I will now more fully describe the effect of the arrangement describedon the water used in the generation of steam. As before described, thefeed-water is supplied first to the cellular jacket A and itstemperature is raised by the absorption of the heat conducted throughthe fire-brick or similar lining of the furnaces. The feed-water ispreferably supplied to the lowest part of the jacket from a tank, thewater-levelin which is maintained but little above the highest part ofthe jacket.

The water heated in the cellular jacket is preferably delivered by thepipe or pipes A connected with the upper part of each section of thejacket, to a tank, from which it is forced into the boiler by means of afeed-pump connected with the feed-pipe B". The pipe A may be connecteddirectly to the feed-pump,

or,if the cell ular j acket A were strong enough to withstand thepressure, the feed water might be forced by the feed-waterpump' into thelower part of the jacket and the upper part of the jacket might beconnected directly 'by the pipe- 13 with the feed-pipe R".

either arrangement the feed-water is heated.

to or nearly to the boiling-point in the cellular jacket, and itstemperature is materially increased in its passage through the feed-pipefrom the upper end of the boiler to the muddrum, where'it is preferablydelivered in a divided state or spray.

\Vhen water is heated, the capacity to hold matter in suspension isdiminished. The feed-water discharged from the feed-pipe in to themuddrum precipitates the impurities contained in it. A large part of thefeedwater enters into the transverse chamber B more concentrated waterdeposits the impurities held in suspension, and the purified waterreenters the water-tubes 13 and some of it the mud-drum B while aportion of the water required mixes with the water descending throughthe circulatingtube B and as-' cending through the annular space betweenthe circulating-tube B and the column B This continuous circulation ofthe water in the boiler, by which the water, made denser by the partialconversion into steam, descends to the mud-drums and reascends incontact with the heating-surface, so facilitates the separation of theimpurities and their precipitation in the mud-drums, where they are notaffected by heat and may be readily blown off, that in practice after anextended use with inferior water not the slightest precipitationofimpurities .or scale is found on the tube-surfaces or tube-sheet of theboiler. Efficiency and durability are secured by this arrangement.

In practice the furnaces are alternately fired. The firing and ash-pitdoors of the furnace that is being fired are open and the draft-openingA controlled by the gate A is closed, while the firing and ash-pit doorsof the otherfurnace are closed and the draftopening A of this otherfurnace is open. Then the other furnace is fired, the gate A isreversed. The gate A may be connected by suitable mechanism with thefurnacedoors, so that by opening the firing-door of a furnace the gateis swung over to close the outlet of this furnace and compel the gasesto pass through the flame-chamber and, the furnace not being fired,through the. draftopening A to the combustion-chamber.

, Having thus described my invention,. I claim as new and desire tosecure by Letters Patent- 1. In combination with a steam-boiler, afurnace divided by a partition into two separate firing-chambers, aflame-chamber in the rear her in the rear of and connecting the twofiring-chambers, and a draft-opening in the front end of thefiring-chambers controlled by a gate, whereby the products of combustionfrom one firing-chamber are made to pass through the flame-chamber andthrough the other firing chamber before entering the tubes of theboiler, as described.

3. In a steam-generator, the combination with the steam-boiler, of afurnace having two separate firing-chambers, a flame-chamber in the rearof and connecting the two firingchambers, a draft-opening controlled bya gate, and a combustion-chamber; the whole inclosed by fire-brick,whereby the products of combustion from one firing-chamber are made topass through the flame-chamber, through and over the fire in the otherfiringchamber and through the combustion-chamber before they enter thetubes of the steamboiler, as described.

4. In combination, a steam-boiler, a furnace divided by a partition intotwo separate firing-chambers, a flame-chamber connecting the rear of thetwo'firing-chalnbers, a draftopening at the front end of thefiring-chambers, a combustion-chamber, and a cellular water-jacketinclosing the furnace, whereby the more perfect combustion of the fuelis secured before the products of combustion enter the tubes of theboiler and radiated heat is transmitted by the brick lining to the waterin the jacket, as described.

5. In combination, a steam-boiler, a brickinclosed furnace divided by apartition into two firing-chambers connected at the rear by aflame-chamber and at the front by a draftopening with acombustion-chamber, of a series of water-tubes, extending through thefurnace, connected with the mud-drum of the boiler and with the boiler,whereby the more perfect combustion of the fuel is secured before theproducts of combustion enter the flues of theboiler and the radiatedheat is 10- cally utilized by the water-tubes, as described.

6. In combination with a steam-boiler and a furnace divided by apartition into two separate firing-chambers adapted to be alternatelyfired, of two separate sections of watertubes, one section for eachfiring-chamber, each section connected with the mud-drum below thefurnace and with the boiler above the furnace, whereby the sections mayadjust themselves to variations in temperature, as described.

7. In a steam-generator, the combination with a vertical tubular boilerhaving a central water-column connected with a muddrum at its lower end,of the transverse chamber B provided with the mud-drums 13 B a series ofwater-tubes 13 and B connections between the water-tubes, the chamber 13and the boiler, and a furnace located on one side of the centralwatercolumn of the boiler, whereby the heat of the fire is exerted onthe water-tubes before the products of combustion enter the fiues of theboiler and the efficiency of the boiler increased, as described.

8. In a steam-generator, the combination with the vertical tubularboiler 13, the watercolumn B the circulating-tube B and the mud-drum Bof the feed-water pipe B and the rose B connected with the feed-waterpipe below the ash-pit, whereby the feed-water is sprayed into themud-drum and the precipitation of impurities facilitated, as described.

9. In combination, avertical tubular steamgenerator, a centralwater-column extending from the lower tube-sheet downward, acirculating-tube within the central water-column, a mud-drum at thebottom of the central water-column, a feed-water pipe extending from thetop of the boiler downward and terminating in the mud-drum, a transversechamber connected with the mud-drum and provided with auxiliarymud-drums, a series of water-tubes connected with the transversechamber, with the boiler and with the muddrums of the transversechamber, and a furnace divided by a partition into two firingchambersand adapted to be alternately fired, as described.

10. In a steam-generator, the combination of the followinginstrumentalities, a furnace divided by a partition into two archedfiringchambers, a semicircular arched flame-chamber connecting the rearof the two firingchambers, an arched combustion chamber above andextending across the width of the firing-chambers, a draft-opening,controlled by a gate, connecting the firing-chambers with thecombustion-chamber, a cellular waterjacket inclosing the furnacestructure, and a steam-boiler connected with the combustionchamber,whereby the fuel is consumed within spaces surrounded by fire-brick andthe products of combustion passed through the tubes of the steam-boiler,as described.

In witness whereof I have hereunto set my hand.

D. M. THOMPSON. WVitnesses:

JosEPH A. MILLER, 13. M. SIMMS.

